This has been the biggest year ever for cyber crime, from Stuxnet, the worm that was deployed to disrupt Iran's nuclear program, to China's attack on Google. Now defenders of Julian Assange and WikiLeaks have launched "Denial of Service" attacks on Visa, MasterCard, PayPal and Amazon. Institutions, including governments, are on the defensive and they're trying to beef up cyber security. But how does cyber crime happen? Is it all technology, or is the human element just as important? Will cyber security mean suppressing free speech?